We can look at the GPU for a comparison of what 'generation' games can be compared to.
Xbox 360: 500 MHz
PS3 : 550 MHz
Wii: 250 MHz
Xbox: 233 MHz
PS2: 147 MHz
Gamecube: 162 MHz
Clearly, Wii doesnt have the graphic capabilities of XBox 360 or Playstation 3, and it barely surpases the graphical capabilities of last generation's graphics leader, XBox. Wii isn't last gen, but its not this gen either. Ofcourse, that doesnt take away from the huge success that Nintendo is having with the Wii.
Another thing to point out is that the system with the lowest GPU sells the best, while the system with the highest GPU sells the least (atleast at this moment for this generation). This would indicate that graphics dont sell consoles, cost sale consoles.
For information's sake, I own an Xbox 360 and a Wii and enjoy them both.
